Electric switch



Aug. 4, 1925.

J. D. HILLIARD ELECTRIC SWITCH Filed April 27. 192.3

2f Inventor* John D.Hi|lia1^d Patented Ang. ei, lQZ

UNITED STATES PTN'T FFC,

JOHN D. HILLIARD, OF SCHENECTADY, NEW YORK, ASSGNOR TO GENERAL ELECTRIC COMPANY, A CQRPORATON 'Oll IilE'i/V YGRK.

ELECTRIC SW'I'JCH.

Application filled April 2*?, 1923. Serial No. 635,128.

Tol @ZZ whom t may vconoce/vn.'

Be it known that l, Jorrit l). Himno-io, a citizen ot the United States, residing at Sachenectady7 in the county oiE Sfhcnectadv, State oit New York, have inventefii ce new and usetul improvements in lillec L,ic Switches, ot which the following is a speciication.

My invention relates to electric switches 't the iuid break type where-in the pre oit the gas generated upon opening the switch tends to cause a reclosing oit the same and the object oi my invention is to provide against such a reelosing ot the switch. It is well known that at each ope/nine' oi? a. fluid break switch under load an arc is drawn at the. switch contacts which., hy the disassociation of the insulating fluid, s denly forms a considerable volume ot Tvihere the constrnction ot the switch operating mechanism includes an o :kerating rod which slides through an opening in the cover ot the vessel enclosing the insiil'ating rluid and the. switch contacts and is moved outwardly to close the switch, the pressure ot gas formed when the. switch opens the circuit under heavy load, and particularly during the existence of ay short circuit on the line controlled hy the switch, may loe sutlicient to cause the switch to reclose. Such a reclosing ot the switch which has previously opened in response to a short circuit frequently has been followed up hy disastrous results. To prevent such reclosing ot the switch` under the conditions nientioned without interfering with the operating movement ot the switch, I have provided a detcnt which normally engages a portion of the. switch operating mechanism to prevent its movement in a direction corresponding to the closing movement ot the switch but which is disengaged hy an electromagnet from such operating mechanism prior to the operation otl the s Yitch actuating` means.

My invention will he hotter understood from the tollowing` description and accompanying drawing, in which Figure l is a diagrammatic view of a Huid break switch and operating mechanism therefor illustrating a preferred form ot my invention; F 2 is a diagrammatic view illustratingy a modification.

Referring now to F l of the drawing, l represents the enclosing` vessel or tank ot ed to Y switch l have shown an electro-magnet com Y prising a solenoid lo which has iulcrunied to its upper portion a lever 'i3 to which the rod il is iivoted. llilhen the solenoid is energized the plunger l-t is li'lted to engage and operato the lever lil to close the switch. le links l5 serve to retain the lever 18 in its raised position correspendingl to the closed position ot the switch.

.in order that the pressure ot gas generated within the tank upon the opening' oi the switch under load or when a short` circu-it occurs on the line may not canUVV the switch to reclose, l have provided a igatchet mechanism comprising a series ot teeth l? formed upon the rod ll which aro normally engaged hy a spring pressed pawl 1S. r[his pawl is pivoted to a support 19 and ias a pin and slot connection as shown with an actuating rod 20, which rodextends lroin opposite ends of a core 2l ot the solenoid rlhe rod 2O carries a bridging nicinloer 93 at the end opposite the pawl which is adel/)ted to electrically connect. contacts and 25a and arranged between and secured to the solenoid and the hridging memher is a tension spring 26. Circuit connections are provided between the two solcnoids l@ and 22 and the mains 2i' to he controlled hy a switch Q8. A resistance 29 is included in the connection between the two solenoA and the contacts Q4 and are connected in the manner shown so that when they are engaged hy the hridging member .13 the solenoid 22 andthe resistance will he short circuited. rllhc value ot the resistance is so chosen that when this resistance added to the resistance oi" the solenoid 2f?, the current will he insnliicient to cause the solenoid l2 to actuate the switch.

1 Considering the parts in the positions shown hy l, the main switch is moved to closed circuit position hy closi the switch 28. This closes a series circuit through both solenoids and the resistance, but 'for the reason stated above, only the clcctromagnet which is connected to the pawl will be actuated. The pawl is thereby withdrawn and the contacts 24 and 25 are bridged by the member 23. rlhe resulting` increase in energization ot the solenoid i2 is suiiicient to cause the main switch to be closed, it being understood that by reason oit the inertia ot the parts, the pawl is not rcturned into position to engage the ratchet teeth 17 before the main switch is 'fully closed. Since the pawl normally enga r the ratchet, pressure within the tank cannot cause the switch to open.

In the modified torni shown in Fig. Q the construction is the same as shown in Fig. l, the diilerencc residing only in the. circuit arrangement. rIhe resistance 29 in this case, is placed between the solenoid i2 and one ot the mains and the contacts Zi and 25 are connected with opposite ends ot the resistance so that when the electromagnet controlling the pawl is actuated the resistance 29 only is short cireuited.

As the operation ot the 'torni illustrated by Fig. 2 is similar to that ot Fig. i which has already been described, a desription of its operation will be omitted.

IVhile I have described a preferred cmbodiment ot my invention together with a single modification thereoi, I do not wish to be limited to the particular terms shown and described as it will be apparent that many modifications thereof may be made without departing trom the scope oi my invention as set orth .in the appended claims.

I'Vhat I claim as new and desire to secure by Letters Patent ot' the United States, is:

l. In a tluid break switch wherein the pressure ot gas evolved tends to move the switch mechanism to closed circuit position, means eii'ective upon the initial movement of the switch mechanism to open circuit position 'for preventing the reclosing ot the switch, means Ylor rendering said means inoperative and means responsive to the operation ot said second means tor moving said switch mechanism to closed circuit position.

2. In a tluid break switch wherein the pressure ot evolved tends to move the switch mechanism to closed circuit position, means tor moving said mechanism to closed circuit position, means 'for controlling said first means, and means controlled by said controlling means tor preventing movement ot said mechanism to closed circuit position, said last means being eti'ective after an initial movement oit said mechanism to open circuit position.

3. In a tluid break switch mechanism wherein the pressure ot gas evolved tends to move the mechanism to closed circuit position, means independent ot the position ot said mechanism for normally opposing movement ot said mechanism to closed circuit position, electromagnetic means tor rendering said means inoperative, means tor moving said mechanism to closed circuit position, and means operated by said electromagnetic means for controlling the operation ot said moving means.

-1-. In a fluid break switch mechanism wherein the pressure ot gas evolved tends to move the` mechanism to closed circuit position, an electromagnet for moving said mechanism to closed circuit position, means tor preventing the reclosing ot said switch due to gas pressure atter an initial opening movement o'l" the switch, electromagnetic means 'for rendering said means inoperative and a switch operated by said electromagnetic means tor controlling` said electromagnet.

In a fluid break switch mechanism wherein the pressure oi' gas evolved tends to move the mechanism to closed circuit position, an electromaguet tor moving said mechanism to closed circuit position, means ior preventing the reclosing ot said switch due to gas pressure after an initial opening movement ot the switch, means tor rendering said means inoperative, a switch tor coiurolling said last means, and a switch operated in response to movement ot said first means 'lor controlling the energization ot said electromagnet.

(i. In a tluid break switch mecl'ianisni wherein the pressure ot gas evolved tends to move the mechanism to closed circuit position, an electromagnct for moving said mechanism to its closed circuit position, a

detent normally engaging said mechanism to prevent said movement alter the switcli has begun to open, an electromagnet il'or withdrawing said detent, and a switch responsive to the position oil said detent vtor controlling the operation ol said electromagnet.

7. In a fluid break switch mechanism wherein the pressure ot gas evolved tends to move the mechanism to closed circuit position, an electromagnet i'or moving said mechanism to its closed circuit position, a ratchet on said mechanism, a detent normally engaging said ratchet to hold said mechanism against movement to closed circuit position, an electromagnet for withdrawing said detent, a switch operated by the latter electromagnet, a source ot current, a control switch, circuit connections between said source, said electromagnets, and said switches whereby when said control switch is closed, said detent is withdrawn and the switch controlled thereby is closed to cause the actuation ot said lirst mentioned eleotromagnet.

In witness whereof, I have hereunto set my hand this C26th day ot April, 1923.

JOI-IN D. IIILLIARD.

soy 

